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</o:shapelayout></xml><![endif]--></head><body lang=EN-AU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>If you did not make any changes to the open_video and add_video functions of the decoding_encoding example, it cannot work. For H264 you need to manually define a set a of H264 private settings before opening the codec.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><a href="http://stackoverflow.com/questions/3553003/encoding-h-264-with-libavcodec-x264">http://stackoverflow.com/questions/3553003/encoding-h-264-with-libavcodec-x264</a><o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Harry<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=DE style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Von:</span></b><span lang=DE style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> libav-user-bounces@ffmpeg.org [mailto:libav-user-bounces@ffmpeg.org] <b>Im Auftrag von </b>Ashwin Chandra - SISA<br><b>Gesendet:</b> Freitag, 08. Februar 2013 00:29<br><b>An:</b> This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter.<br><b>Betreff:</b> Re: [Libav-user] Problem with using libavcodec with AV_CODEC_ID_H264<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>To be clearer, I modified the decoding_encoding.c example in ffmpeg to cause the problem.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>I basically changed the video_encode_example() to encode 1 second worth of video and then flush the delayed frame. The code below is exactly the same except 25 frames was replaced with 1 frame.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>Now if I take this code block and duplicate it again, so that it basically runs twice, the second </span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>avcodec_encode_video2() will hang.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas;color:green'>/* encode 1 second of video */</span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>for</span>(i=0;i<1;i++) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> av_init_packet(&pkt);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> pkt.data = NULL; <span style='color:green'>// packet data will be allocated by the encoder</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> pkt.size = 0;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> fflush(stdout);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:green'>/* prepare a dummy image */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:green'>/* Y */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>for</span>(y=0;y<c->height;y++) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>for</span>(x=0;x<c->width;x++) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:green'>/* Cb and Cr */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>for</span>(y=0;y<c->height/2;y++) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>for</span>(x=0;x<c->width/2;x++) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> frame->pts = i;<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:green'>/* encode the image */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> ret = avcodec_encode_video2(c, &pkt, frame, &got_output);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>if</span> (ret < 0) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> fprintf(stderr, <span style='color:#A31515'>"Error encoding frame\n"</span>);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> exit(1);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>if</span> (got_output) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> printf(<span style='color:#A31515'>"Write frame %3d (size=%5d)\n"</span>, i, pkt.size);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> fwrite(pkt.data, 1, pkt.size, f);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> av_free_packet(&pkt);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:green'>/* get the delayed frames */</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>for</span> (got_output = 1; got_output; i++) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> fflush(stdout);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>if</span> (ret < 0) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> fprintf(stderr, <span style='color:#A31515'>"Error encoding frame\n"</span>);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> exit(1);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>if</span> (got_output) {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> printf(<span style='color:#A31515'>"Write frame %3d (size=%5d)\n"</span>, i, pkt.size);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> fwrite(pkt.data, 1, pkt.size, f);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> av_free_packet(&pkt);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <a href="mailto:libav-user-bounces@ffmpeg.org">libav-user-bounces@ffmpeg.org</a> [<a href="mailto:libav-user-bounces@ffmpeg.org">mailto:libav-user-bounces@ffmpeg.org</a>] <b>On Behalf Of </b>Ashwin Chandra - SISA<br><b>Sent:</b> Thursday, February 07, 2013 3:08 PM<br><b>To:</b> <a href="mailto:libav-user@ffmpeg.org">libav-user@ffmpeg.org</a><br><b>Subject:</b> [Libav-user] Problem with using libavcodec with AV_CODEC_ID_H264<o:p></o:p></span></p></div></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US>I have some code that takes a running stream of uncompressed video data and encodes it using </span><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>AV_CODEC_ID_H264.<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>The sequence I follow is<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo2;text-autospace:none'><![if !supportLists]><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>Call avcodec_encode_video2 on the AVFrame which contains my uncompressed frame.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo2;text-autospace:none'><![if !supportLists]><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>Call avcodec_encode_video2 again passing NULL in the AVFrame parameter.<o:p></o:p></span></p><p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo2;text-autospace:none'><![if !supportLists]><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>Repeat 2. Until a frame arrives from the encoder.<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'>This seems to work fine if the codec is MPEG2, but with H264, it hangs inside avcodec_encode_video2 at step 2) on the second frame. I don’t have debug symbols and can’t figure out why. Does there need to be a minimum set of uncompressed data in the encoder before trying to flush out an encoded frame for H264? If so, how do I know when it is safe to flush a frame?<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-US style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p></div></body></html>